Fireplace structure

ABSTRACT

A fireplace of sheet metal construction having a firebox with the rear wall of a reverse curve construction to provide a convex reflecting surface for radiating heat into the living space, and a hearth having an air discharge opening connected to outside air for providing an inflow of air to the fireplace to satisfy draft requirements. A housing is disposed around the firebox and an air passage containing baffles is disposed therein for either up or down flow of air to provide supplemental heating for the room. A generally U-shaped upstanding wall may be provided around the hearth in which the opening for outside air is disposed, whereby the air is directed over the surface of the hearth to the lower portion of the firebox at the base of the fire.

D United States Patent 1191 Bell [45] Dec. 16, 1975 1 FIREPLACE STRUCTURE 26,386 9/1883 Germany 126/121 [76] lnventor: Ralph E. Bell, 308 E. Wabash Ave.,

Wakarusa, Ind 46573 Primary E.ranziner-W11liam F. ODea Assistant E.\'aminer-Peter D. Ferguson Filed: 1974 Attorney, Agent, or FirmMarmac1uke Hobbs [21] App]. No.: 444,273

[57] ABSTRACT 521 US. Cl 126/121; 126/143 A fireplace of Sheet metal Construction having a fire- [51] Int. Cl. F24B 7/00 box with the rear wall of a reverse Curve Construction [58] Field of Search 126/120, 121, 131, 143 to Provide a Convex reflecting Surface for radiating heat into the living space, and a hearth having an air 56] References Ci discharge opening connected to outside air for provid- UNITED STATES PATENTS ing an inflow of air to the fireplace to satisfy draft re- 30 8 quirements. A housing is disposed around the firebox 112451282, 18/133? 225;???1:::;1:"'""'"""'"213:: 132/15? and Passage contaimng is e 1,711,090 4H9 Ford et aL v v l H 126/120 therem for either up or down flow of an to provlde 2,470,430 5/1949 Carter 126/143 Supplemental heatmg for the room A generally U- 2,s21,975 2/1958 Thulman 126/120 shaped upstanding Wall may be Provided around the 3'096754 7/1963 Howey 126/120 hearth in which the opening for outside air is disposed, 3,180,332 4/1965 Grushkin whereby the air is directed over the surface of the 3,744,477 7/1973 Andrews 126/120 hearth to the lower portion of the firebox at the base FOREIGN PATENTS OR APPLICATIONS of the 764,843 1/1957 United Kingdom 126/143 9 Claims, 6 Drawing Figures r 24 iii 4/42 E ii 40 20\m 3 US. Patent Dec. 16, 1975 Sheet 1of2 3,926,174

US. Patent Dec. 16,1975 Sheet20f2 3,926,174

FIREPLACE STRUCTURE Many modern homes and mobile and modular homes are built of light construction and often do not have, nor are they adapted to contain, a conventional brick or stone fireplace which, because of its weight, must have a solid foundation for support. Mobile homes cannot support the masonry type fireplace and be transported over the highway, and are not adapted to have a conventional fireplace installed therein after the mo bile home has been delivered and placed on a supporting structure. Further, most modern conventional homes and mobile and modular homes are built so nearly air tight that there is sometimes insufficient inflow of outside air to support normal combustion of the furnace or other flame type space heating unit, and fireplaces are well known for the large outflow of air which must be replaced either through a partially opened window or through cracks around doors and windows, to maintain proper operation without smoking. It is therefore one of the principal objects of the invention to provide a fireplace structure which is relatively light weight in construction and can be supported by the floor structure of a modern home or mobile or modular home without the necessity of a foundation therefor and without danger of fire to the building or vehicle structure, and which can be installed any place in the home where a flue can be opened to the outside.

Another object of the invention is to provide a rear wall configuration for a fireplace capable of radiating the heat waves over a wide area in the living space, in stead of reflecting it principally onto the floor in front of the fireplace, and which is constructed in combination with an outside air inlet passage which discharges the air toward the fireplace from an opening in front of the fireplace.

Still another object of the invention is to provide a fireplace which is so constructed and designed that the rear and sides of the firebox are enclosed by an air flow passage or passages for heating air, either from the outside or from the living space, and for discharging the heated air into the living space either at registers in or near the floor, or near the ceiling.

A further object is to provide a fireplace of the aforesaid type in which fins and/or baffles are provided in the air passages surrounding the firebox to give maximum efficiency to the unit for heating the living space both by radiation and by circulating air, and which is adapted to circulate the air in either direction up or down through the air passages.

Another object of the invention is to provide a fireplace structure which is relatively simple in construction and can be prefabricated and delivered in two major easily assembled sections, and which can easily be installed in either new or old buildings or vehicle structures without making any substantial changes in the construction of the structures.

Additional objects and advantages of the invention will become apparent from the following description and accompanying drawings, wherein:

FIG. 1 is a perspective view of a fireplace embodying the present invention;

FIG. 2 is a vertical cross sectional view through a conventional dwelling and through the present fireplace, illustrating the manner in which one embodiment of the invention may be installed;

FIG. 3 is a fragmentary vertical cross sectional view, similar to that shown in FIG. 2, illustrating a modified form of the present invention;

FIG. 4 is a perspective view of the rear side of the present fireplace, showing the rear side with the housing removed therefrom;

FIG. 5 is a vertical cross sectional view in a somewhat schematic form, showing a modification and illustrating the manner in which it may be operated; and

FIG. 6 is a vertical cross sectional view similar to that shown in FIG. 5, showing a further modification of the invention and illustrating the manner in which it operates.

Referring more specifically to the drawings, and to FIGS. 1 and 2 in particular, numeral 10 indicates generally a fireplace embodying the present concept, numeral 12 indicates a conventional dwelling having foundation l4, joists l6, floor 18, wall 20, ceiling 24, and roof 26. The fireplace 10 is shown installed in the dwelling, indicating by arrows the direction of air flow and radiation in the particular embodiment of the invention shown. The fireplace structure of the present invention may be readily adapted to a variety of different dwelling structures, and may be installed in mobile and modular homes, with very few changes in the basic construction of the units.

One of the features of the present invention is its relatively light weight, which permits installation of the fireplace in the dwelling or living space without the provision of a special foundation or other supporting structure for the unit. The one shown in FIGS. 1 and 2 consists of a housing or shell 30 having a firebox 32, face 34, throat and smoke shelf 36 and 38, and flue 40. A damper may be placed at any one of a number of locations above the firebox, the location shown in the drawing being in the flue as indicated at numeral 42. The flue extends through the ceiling and roof and is insulated from the structural members thereof by a shroud 44 surrounding the flue. A cap 46 is preferably placed over the flue in order to prevent rain water from entering the flue and fireplace. The entire structure thus far described is constructed of sheet metal sections, welded, or otherwise joined together to form an integrated unit. The housing 30 and flue 40 are normally, and possibly in most instances necessarily, made in several separate parts for shipping and easy installation. The hearth 50, of special construction which will be described in greater detail hereinafter, is shown as a recessed type with a U-shaped wall member 52 surrounding it on the two sides and front. A small hood 54 is provided over the opening and forms in effect the lintel for the face of the fireplace above the opening of the firebox.

The firebox consists of side walls 60 and 62, bottom 66, and rear wall 68, the rear wall shown being of a special curved design to provide a reflective surface for radiating the heat waves over a relatively wide area in the living space. Most conventional fireplaces have rear walls with a first vertical surface and then a straight forwardly sloping surface, the sloping surface causing the heat waves to radiate downwardly toward the floor near the hearth. The configuration of the rear wall of the present fireplace distributes the radiated heat over a much wider area than that provided by the conventional rear wall, as the flames and radiated heat waves from the fire, preferably in a grate 70, impinge on the surface of the rear wall and are reflected therefrom. The grate shown in the fireplace holds the wood or other fuel used in the fireplace; however, andirons may be used if desired.

As seen in FIG. 2, the fireplace structure is seated directly on floor 18, which is supported by joists 16,and with no special foundation used to support the fire place. The fireplace may be set firmly against the wall or across a corner of the room; however, in either type of installation the heat from the fireplace-is dissipated by the air passages or conduits 72 and 74 behind and beneath the firebox. Further insulation may be used if desired; however, the circulating air normally is sufficient to provide a safe installation.

Since a fireplace requires a substantial inflow of air to replace the air flowing out the flue, the present fireplace is designed to provide the required air so that the living space is not cooled by air inflow through cracks or a partially opened window. In the embodiment shown in FIG. 3, the draft for the fireplace is provided through an air conduit 80 connected with outside air through a vent 82 in the upper part of foundation l4 and to an outlet port 84 on the inner side of section 86 of U-shaped wall member 52 surrounding hearth 50. The inflowing air through conduit 80 is discharged directly toward the fireplace over the hearth from port 84, and flows directly into the fireplace opening. Thus the temperature of the air from the outside does not cool the remainder of the house but permits the fire to burn effectively and provide radiated heat directly to the room.

The heat dissipated through the side and rear walls of the firebox is utilized by an effective conduit and baffling system shown in FIGS. 4, and 6. The vertically spaced baffles 90 are joined by welding or other suitable connecting means to the face 34 and to the rear and side walls of the firebox. In order to give the air an opportunity to absorb effectively the heat as it passes either upwardly or downwardly in the passages, a series of alternate side holes 92 in every other baffle, and a series of vertically arranged, alternate rear holes 94 cause the air to circulate to and'from the sides and center of the air passage at the rear of the firebox. The schematic diagrams of FIGS. 5 and 6 illustrate the manner in which this system operates, causing the air to flow through a circuitous route in passing from an air inlet, such as registers 96 and'98. When the air is admitted through registers 96 on opposite sides of housing 30, the air flows by convection upwardly through passage 99, and is discharged through opening 98 near ceiling 24. A damper 102 may be used to open and close passage 99 as required to obtain optimum'comfort in the living space.

The embodiment illustrated in FIG. 6 is essentially the same as FIG. 5, with the exception that a motor driven blower 104 causes the air to flow downwardly from register 98 through passages 99 and outwardly through a passage 106 and hot air outlets 'or registers 108 and 110. The outlet registers may be any place in the living space, and if desired, on the opposite side of the room from the fireplace. Passage 112 connecting passage 99 to register 98 may also 'be connected to the outside so that an inflow of additional cool air is available for combustion. v

In the operation of the present fireplace, when a fire has been started and is burning in the firebox, the flame normally impinges on the rear wall, thus heating the rear wall sufficiently to cause radiation into the living space. In view of the configuration of the reversed curve, shown best in FIGS. 1 and 2, and resembling in LII cross section a modified S shape. the heat is radiated upwardly, horizontally and downwardly to give effective heating to the living space. The smoke passes through the throat into the smoke chamber and then upwardly through the flue. thus providing additional heat to the room, either by direct radiation from the flue structure or through air flow passage 112 disposed adjacent the front surface or surrounding the flue. The inflow of air is automatically provided through conduit 80, and the discharge of air through port 84 provides an effective supply of air for the fire in grate 70. The structure for supplying outside air to port 84 is only illustrative of a number of different ways in which this may be done. In any event, however, the discharge port 84 is preferably in section 86 of wall member 52, thus providing a direct flow of air into the firebox beneath the burning fuel in the grate. The efficiency of the fireplace likewise automatically operates either by convection, as illustrated in FIG. 5, or by forced air created by blower 104, to absorb the heat surrounding the rear side of the firebox and discharge it into the living space.

A glass screen or door may be used and air flow from outside air may be introduced directly into the firebox as at ports 116 on either side of the grate or in the bottom. The parts are connected by a conduit to the outside air conduit and a valve or damper may be used to Switch the air flow between ports 84 and 116 depending upon whether the glass door is opened or closed.

In view of the type of sheet iron construction, the fireplace is relatively light in weight and can easily be installed in a dwelling, mobile or modular home and provided with a suitable flue through the ceiling and roof and a cold air supply through the floor and/or foundation. Thus, the present fireplace is capable of being readily installed in old or new construction and used safely therein, utilizing primarily the air flow surrounding the firebox and beneath the hearth for insu lating the fireplace from the supporting members.

While only one embodiment and several modifications of the present fireplace have been described in detail herein, various changes and modifications may be made without departing from the scope of the inv ention.

' I claim:

1. A prefabricated movable fireplace structure comprising walls defining a housing having a bottom, two side walls and a rear wall, a firebox in said housing having a bottom, two side walls and a rear wall of sheet metal and an open front, said firebox walls being spaced from the respective walls of said housing to form an air passageway beneath and at the sides and back of the firebox to heat the air in the passageway, and to provide an insulating effect for the walls and bottom of the housing, baffles joined integrally with the rear wall of said firebox and disposed in said passageway along the back of said firebox for dissipating heat from the firebox into the air flowing in said passageway, means forming outlets near the bottom for directing heated air outwardly at a low level from said passageway, blower means for moving the air downwardly in said passageway around said baffles, a flue connected to said firebox andextending upwardly therefrom, and a hearth disposed in front of said firebox and having an air conduit means with an outlet opening facing the front of the firebox for supplying air from an outside source to the firebox.

2. A fireplace structure as defined in claim 1 in which an upstanding wall of generally U-shaped configuration surrounds the hearth and contains said outlet opening facing the front of the firebox.

3. A fireplace structure as defined in claim 2 in which said baffles are provided with openings therethrough and are disposed horizontally in said air passageway to create a circuitous flow of air through said passageway.

4. A fireplace structure as defined in claim 3 in which the rear wall of said fireplace has a reverse curve therein providing a convex forwardly facing surface in the upper portion thereof for radiating heat to the living space in which the fireplace is located.

5. A fireplace structure as defined in claim 1 in which said baffles are provided with openings therein and are disposed horizontally in said air passageway to create a circuitous flow of air through said passageway.

6. A fireplace structure as defined in claim 5 in which walls define a passage above said housing forming an extension of said air passage in close proximity to the flue above said housing and an opening near the top thereof for air flow.

7. A fireplace structure as defined in claim 1 in which the walls of said housing and hearth are constructed of sheet metal.

8. A fireplace structure as defined in claim 1 in which the rear wall of said fireplace has a reverse curve therein providing a convex forwardly facing surface in the upper portion thereof for radiating heat to the living space in which the fireplace is located.

9. A fireplace structure as defined in claim 1 in which a port for outside air is located within the firebox. 

1. A prefabricated movable fireplace structure comprising walls defining a housing having a bottom, two side walls and a rear wall, a firebox in said housing having a bottom, two side walls and a rear wall of sheet metal and an open front, said firebox walls being spaced from the respective walls of said housing to form an air passageway beneath and at the sides and back of the firebox to heat the air in the passageway, and to provide an insulating effect for the walls and bottom of the housing, baffles joined integrally with the rear wall of said firebox and disposed in said passageway along the back of said firebox for dissipating heat from the firebox into the air flowing in said passageway, means forming outlets near the bottom for directing heated air outwardly at a low level from said passageway, blower means for moving the air downwardly in said passageway around said baffles, a flue connected to said firebox and extending upwardly therefrom, and a hearth disposed in front of said firebox and having an air conduit means with an outlet opening facing the front of the firebox for supplying air from an outside source to the firebox.
 2. A fireplace structure as defined in claim 1 in which an upstanding wall of generally U-shaped configuration surrounds the hearth and contains said outlet opening facing the front of the firebox.
 3. A fireplace structure as defined in claim 2 in which said baffles are provided with openings therethrough and are disposed horizontally in said air passageway to create a circuitous flow of air through said passageway.
 4. A fireplace structure as defined in claim 3 in which the rear wall of said fireplace has a reverse curve therein providing a convex forwardly facing surface in the upper portion thereof for radiating heat to the living space in which the fireplace is located.
 5. A fireplace Structure as defined in claim 1 in which said baffles are provided with openings therein and are disposed horizontally in said air passageway to create a circuitous flow of air through said passageway.
 6. A fireplace structure as defined in claim 5 in which walls define a passage above said housing forming an extension of said air passage in close proximity to the flue above said housing and an opening near the top thereof for air flow.
 7. A fireplace structure as defined in claim 1 in which the walls of said housing and hearth are constructed of sheet metal.
 8. A fireplace structure as defined in claim 1 in which the rear wall of said fireplace has a reverse curve therein providing a convex forwardly facing surface in the upper portion thereof for radiating heat to the living space in which the fireplace is located.
 9. A fireplace structure as defined in claim 1 in which a port for outside air is located within the firebox. 